Vacuum-pressure frame



I A. T. KOPPE. VACUUM PRESSURE FRAME. APPLICATION FILED NOV. 51 1919.

1,396,962, v Patented N0v.15,192 1.

2 SHEETS-SHEET I.

ale/wander T/{OPPQ A. T. KOPPE.

VACUUM PRESSURE FRAME. APPLICATION FILED NOV. 5. 1919.

Patented No vi 15, 1921 2 SHEETS-SHEET 2.

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az exarzaer .Z' Ko a 0e I Avwswraw UNITED STATES ALEXANDER '1. KOIPPE, DE LOS ANGELES, CALIFORNIA, ASSIGNOB, TO OFFSET DIRECTO- PATENT OFFICE.

PLATE COMPANY OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

VACUUM-PRESSURE FRAME.

T 0 all whom it may concern Be it known that I, ALEXANDER T. Korrn, a citizen of the .United States, residing at Los Angeles, in the county of'Los Angeles and State of California, have invented certain new and useful Improvements in Vacuum-Pressure Frames, of which the following is a specification.

This invention relates to an improvement in vacuum pressure frames for photographic negatives, and particularly to a pressure frame for securing the negative in contact with a surface on which the negative is to be photographically reproduced, as for example, the press plate of a machine for making offset press plates.

In making offset press plates, particularly as described in connection with Patent No. 1,277,429, issued to me September 3, 1918, the negative is applied directly to the press plate for reprodu'ction,-and this requires a means for positively fixing the negative in close contact with the press plate.- The means described in such patent included a heavy glass member, applied directly to the negative with desired pressure. This pressure plate exerted an even pressure on and throughout the negative, and in the event the negative was slightly warped or. distorted, an almost certain breaking of the negative resulted.

Thepresent invention is designed to entirely overcome the liability of breaking the negative, and this without sacrificing any of the advantages of the previously nec-- essary heavy pressure plate. The improved pressure plate comprises two frames, one to rest on the press plate, and having an inner marginal edge within which the negative is to be placed, and a second frame to rest on the marginal edge of the first frame and on the edge of the negative. The air is then exhausted from beneath the second frame and inner marginal edge of the first frame, causing the negative to be held with proper pres sure on the press plate. As the inner section, or negative bearing frame engages only the marginal edge of the negative, and is itself particularly constructed to compensate for irregularities, there is no liability of breaking the negative, nor of sacrificing that Specification of Letters Patent.

Patented Nov. 15, 1921.

Application filed November 5, 1919. Serial No. 335,968.

close contact of the negative and press plate necessary for proper reproduction.

In the drawings z.-

F gure 1 is a view of the outer or position ng frame section of the improvement.

F g. 2 is a section on line 22 of Fig. 1.

Fig. 3 1s a plan of the .inner or bearing frame section of the improvement.

F g. 4 1s .a section on line 4-4 of Fig. 3.

Fig. 5 1s a plan showing the improved frame applied to a press plate.

Fig. 6 is an enlarged section, on the line 66 of Fig. 5.

The improved vacuum pressureframe, as here. shown, comprises an outer frame sect1on 1, hereinafter termed the positioning sect1on,and an inner frame section 2, hereinafter termed the bearing section.

The positioning section is of open rectangular construction, the sides and ends being of bar form, as at3. The lower side or surface of the positioning section is formed adjacent the outer edge with a channel 4 to receive a sealing strip 5, preferably of rubber, and inwardly of the channel 4 is cut awayto form an air-channel 6. Projecting inwardly and in line with the bottom of the section is a lip or flange 7, the inner edge of which defines the opening within the positioning section for receiving the negative. 7

The bearing section 2-is made up of a more or less flexible strip 8 of rectangular outline, that is with side and end bars. The lower surface of this strip 'is channeled at 9, the

channel extending longitudinally of each side and. end bar and merging one into another, so that the'channel extends uninterruptedly throughout the linear length of the section. This channel 9 is preferably reinforced to prevent collapse or distortion by a thin'inetallic strip 10, as shown, and the upper surfacesof the end and side bars making up the section are also provided with rein orcing strips 11 of metal or the like. A particularly im' rtant vfeature of the reinforcing of the c annel 9 and of the end and side bars, is' that theweinforcing strips in both instances terminate adjacent but free of contact with the adjacentreinforcing strip. This, as will be apparent, provldesa substantial reinforce, but yet-avoids that r1- gidity of the frame or section which would result from a complete and uninterrupted reinforcing. The meeting portions of the side and end bars are thus wholly free of reinforcing, and hence to a limited extent will permit independent yielding or distortion of the side and end bars.

When applied to the press plate, as 12, which in turn is supported on a base plate 13, resting on a'foundation 14, the positioning frame l'is applied directly to the face of the press plate so as to outli'ne that portion of such press plate to be occupied by the negative. It will be understood that certain registry marks are arranged on the press plate for correct placement of the negative. The negative 15 isthen applied, in proper position within the flange 7 and directly on the press plate. In this position,'it will be noticed that the interior dimensions of the flange 7 are somewhat greater than the exterior dimensions'of the negative, to thereby permit adjustment of the negativeas may be indicated by the register marks, without disturbing. the positioning section 1. The positioning frame is designed to rest upon the press plate, or more exactly to be .sup-

' ported by the sealing strip 5, so that the hottom of the positioning section inwardly of the sealing strip is spaced from the surface of the press plate, and the upper surface of the flange 7 substantially in line with the upper surface of the negative. It is therefore preferred that the section 1 be comp-aratively heavy, and for this result such section is made of metal.

Following the proper positioning of the negative, the bearing section 2 of the improved frame is applied, with the lower surface margin outwardly beyond the channel 9, resting on the flange 7 of the section .1, while the lower margin surface inwardly of the channel 9 rests on the negative, near the edge thereof. The junction of the section 1 with the press plate is sealed by the strip 5, while the space between the flange '7 of the section 1 and the negative is sealed by the bearing section 2. The air is then exhausted from beneath the section 1 inwardly of the sealing strip 5, as by a suction apparatus (not shown), the tube 16 from which extends through the bar of the section 1, and may, if preferred form a more or less permanent part thereof. This exhaustion of the air causes the bearing section 2 to press upon the flange and negative and force the latter into that close contact, with the press plate necessary 'for proper results.

The relative yielding between the end and side bars of the section 2, are important, as thereby any warped condition of the negative,'exp-resse d in a distortion of its edge, or any irregularities of the flange .7 will be compensated for in the relative movement of while of improved result in such use, the

vacuum pressure frame of this invention is of course of such construction as to adapt it to other uses in negative holding than the one specifically shown and referred to.

Having thus described the invention, what is claimed as new, is

1. A vacuum pressure device for a photographic plate disposed on a plate support, said device comprising a frame, spaced sealing members carried by said frame, one of said sealing members being positioned to engage the plate adjacent its marginal edges, the other sealing member being positioned to engage the plate support and means of communication for exhausting the air from beneath the frame.

2. A vacuum pressure frame for negatives, comprising frame sections to rest upon the negative support and on the negative, means for sealing the cooperation of the frame sections with said support and with the negative, and means of communication for exhausting the air from beneath the frame sections.

3. A vacuum pressure frame for negatives, comprising a positioning frame section to rest upon a support for the negative, abearing frame to rest on said negative and on the positioning frame, and means of communication for exhausting the air from beneath said. frames. 1

1. A vacuum pressure for holding negatives in fixed relation to a surface for reproduction, comprising a positioning frame sec-. tion to rest on said surface beyond the negative-engaging portion thereof, a bearing frame section to rest on said positioning frame and negative, and means of communication for exhausting the air from the space underlying the bearing frame section.

5. A negative pressure frame, comprising a two-part frame, one part being adapted to be arranged beyond the edge of the negative. and the other part being adapted to bear on the first mentioned part and on the negative adjacent the edge thereof.

6. A two-part negative pressure frame, comprising a section adapted to surround the edge of the negative, a section to rest on said first section and on the negative, and means of communication for exhausting the air from below said sections.

7.A two part negative pressure frame, comprising a section to surround the negative in spaced relation to the edge thereof, a second section of an outline form corresponding to the outline form of the negative, said second section being adapted to rest on the first mentioned section and negative, the second section having sealing cooperation with the first mentioned section and with the negative. i

8. A two part negative pressure frame, comprising a positioning section within which the ne ative is arranged, a sealing strip carried by the positioning section to engage the support on which the negative is to be held, and sealing strips carried by the bearing section to engage the positioning section and negative.

9. A two part pressure frame for nega-, tives, comprising a positlomng section, and

a bearing section, said bearing section being of yieldable material and of outline form, and reinforcing strips secured to the bearing section except at predetermined ortions thereof, ,whereby the bearing is r1 id for bearing purposes while being also yleldable at the non-reinforced portions.

- 10. A two part pressure frame, comprising a positioning section, and a rubber hearing section of outline form having reinforcing strips secured thereto except for predetermjined portions, as and for the purposes state 11. A two'part presure frame, comprising a positioning section, and a rubber bearing section of rectangular form having a channel in the under surface, and reinforcing strips for said section terminating short of the corners thereof.

12. A vacuum pressure frame to secure a negative on a press plate, comprising a positioning frame to rest upon said press plate, a bearing frame to engage said positioning frame and the negative adjacent the edge thereof,and means of communication for exhausting the air from between said frames andpress plate.

13. A vacuum pressure frame to secure anegative on a press plate, comprising a positioning frame of negative outline form to rest on the press plate to define the negative receiving area thereof, said frame having a lip arrangedjust beyond the negative edge when in position, and a means for sealing the junction between the .lip and negative to permit air exhaustion from beneath such frame, said means bearing on the negative with a pressure proportionate to the degree of vacumn..

14. A vacuum two part pressure frame, comprising a positioning frame section, a sealing strip secured to the lower edge thereof, a lip projecting from the inner edge thereof, and a bearing frame section having spaced sealing ortions projecting from the lower surface t ereof.

In testimony whereof I aflix my signature.

ALEXANDER T.' KOPPE. 

